Two bugs were discovered and fixed for the original minimig board, and a new release was prepared.

The first bug was in the minimig blitter implementation, which was missing an undocumented feature of the original Amiga chipset. When using the blitter in line mode, the first pixel of the line is written to D pointer address, and all subsequent pixels are written to C pointer address. This bug was obvious in demos like SushiBoyz & Sunglasses by Ghostown, Vectorize by RSi, etc.

The second bug was a special undocumented feature of Denise / Agnus when number of bitplanes in BPLCON0 is set to 7. In this case, Denise enables six bitplanes, but Agnus DMA sequence only fetches four bitplanes. This way, the remaining two bitplanes can be updated ‘manually’ with CPU / Copper writes. This bug was seen in demos like SushiBoyz by Ghostown, Sliced&Diced by Dekadence, etc.

Both fixes, together with my previous addons to the minimig core for the original minimig board are available in the new release minimig-rel4.

Head over to the Original minimig page, grab your copy and enjoy your minimig!